/**
 * author: ZhangTao
 * data: 2014-10-21
 * 
 * 用法：  data-options="onLoadSuccess:function(){$(this).datagrid('autoMergeCells');}"
 */
$.extend($.fn.datagrid.methods, {
	autoMergeCells : function (jq, fields) {
		return jq.each(function () {
			var target = $(this);
			if (!fields) {
				fields = target.datagrid("getColumnFields");
			}
			var rows = target.datagrid("getRows");
			var i = 0,
			j = 0,
			temp = {};
			for (i; i < rows.length; i++) {
				var row = rows[i];
				j = 0;
				for (j; j < fields.length; j++) {
					var field = fields[j];
					var tf = temp[field];
					if (!tf) {
						tf = temp[field] = {};
						tf[row[field]] = [i];
					} else {
						var tfv = tf[row[field]];
						if (tfv) {
							tfv.push(i);
						} else {
							tfv = tf[row[field]] = [i];
						}
					}
				}
			}
			$.each(temp, function (field, colunm) {
				$.each(colunm, function () {
					var group = this;
					
					if (group.length > 1) {
						var before,
						after,
						megerIndex = group[0];
						for (var i = 0; i < group.length; i++) {
							before = group[i];
							after = group[i + 1];
							if (after && (after - before) == 1) {
								continue;
							}
							var rowspan = before - megerIndex + 1;
							if (rowspan > 1) {
								target.datagrid('mergeCells', {
									index : megerIndex,
									field : field,
									rowspan : rowspan
								});
							}
							if (after && (after - before) != 1) {
								megerIndex = after;
							}
						}
					}
				});
			});
		});
	}
});
